1. Field of the Invention
The present invention provides a means for determining whether a patient has volume dependent hypertension and, more specifically, it provides such a method based upon determining if a substantial reduction in phosphorylation of a specific protein exists. The invention also relates to a diagnostic apparatus employable in making such determination.
2. Description of the Prior Art
Elevated blood pressure or hypertension has long been recognized as a health problem. It is a very common disease which can have widespread effects on a patient's body and frequently, unlike numerous other diseases, is asymptomatic.
Despite known means of measuring blood pressure of a patient as by a sphygmomanometer, for example, there is lacking an accurate reliable means of detecting the presence of volume dependent hypertension involving higher arterial blood pressure by use of a body specimen, such as blood serum or blood plasma.
From a pathogenic standpoint, essential hypertension may be divided into two broad categories (a) volume expansion, hypertension, and (b) vasoconstriction hypertension. It has been estimated that about 30 to 40 percent of human essential hypertension may be permanently related to volume expansion hypertension, especially in certain demographic groups. Previous studies participated in by the present inventor have demonstrated an alteration in the phosphorylation of a proximal tubular membrane protein following acute saline expansion of the experimental rat (Puschett et al. Volume Expansion Induced Changes in Renal Tubular Membrane Protein Phosphorylation, Biochem. Biophys. Res. Commun., 143: pp. 74-80 (1987)).